Nutraceuticals and supplements are commonly used in veterinary and human medicine for complementary treatment of many diseases. Many products claim to have medical benefits in preventing, treating or curing any number of illnesses.

Any compound with these kinds of statements on the label should be regulated as a drug and therefore approved by the FDA. Unfortunately, many companies don't follow this rule, and the FDA chronically ignores breaches if the products don't appear harmful.

When a product is regulated by the FDA, it must meet specific manufacturing and quality standards. Because there is no corresponding regulatory body for nutraceuticals, it can be difficult to assess some products.

Studies have shown that nutraceuticals can contain impurities like heavy metals, bacterias and molds. They can have variable quantities of active ingredients from batch to batch, resulting in unreliable effectiveness.

But not all products are bad! Here are some general guidelines for selecting products of higher quality:

Price - cheaper compounds are less likely to offer quality products, particularly in fish oils and joint support products like chondroitin. High price certainly doesn't guarantee quality, but it's safe to say that you often get what you pay for.

Lot number and expiration date - if the product doesn't list this vital information, it's impossible to track the manufacturing of your bottle in case of contamination. You also can't verify the "best by" date, which is important when determining if a product should be replaced.

Monograph - This is a registration with the US Pharmacopeia, documenting accuracy of ingredient labeling. There is a general USP veterinary page (requiring a free registration) and the USP Dietary Supplement Verification Program page, which provides a list of suppliers who have voluntarily submitted their products for verification. (Note: this doesn't mean that products NOT verified by the USP DSV are of poor quality, but simply that these manufacturers have made extra effort.)

Claims of safety or effectiveness - if a nutraceutical claims a medical benefit, there should be a New Animal Drug Application (NADA) number accompanying that product. While this is mandated by law, it's often ignored. A NADA number tends to suggest higher quality, because the manufacturer has bothered to abide by FDA regulations.

Ingredient list - All ingredients should be listed on the label in order of magnitude based on weight. Products withholding this information with claims of 'proprietary blends' cannot be sufficiently evaluated and should be avoided.

Clear instructions for use

Scientific evidence - each product should have proof to support its claims, preferably through independent scientific studies. Ideally, these studies should be peer-reviewed and published.

Beware of testimonials - companies promoting testimonials in place of valid research to support their claims should be viewed skeptically.

Evaluating the safety of a nutraceutical has two parts. First, the active ingredients can be evaluated. Are they recognized as safe, and suitable for treating your pet's condition?

Second, check the quality of the ingredients. If they're procured from reputable sources, their risk of contamination is lower. Furthermore, products using quality ingredients are more likely to have consistent formulas and quantities of active ingredients from batch to batch.

More difficult is evaluating the effectiveness of a nutraceutical. You can ask the manufacturer about a specific formulation, and from there your veterinarian can evaluate possible negative side effects, and expected benefits.

You can also request copies of published studies or articles demonstrating the effectiveness of the product. For example, those peer-reviewed studies we mentioned earlier would have documentation proving the claims of a nutraceutical.

Other important questions to consider before purchasing a nutraceutical:

- Did the published article or study use the same dosage that I'm administering?

- Were the studies peer-reviewed or published by a reputable source?

- What other medications is my pet receiving, and how might this nutraceutical interact with them?

- What work has been done to verify the safety of this dosing schedule?